Biden expresses skepticism about Putin's comment on possible use of nuclear weapons in Ukraine

U.S. President Joe Biden expressed skepticism on Thursday about Russian President Vladimir Putin's comment that he had no intention of using a nuclear weapon in Ukraine.

Putin, in a speech earlier in the day, played down a nuclear standoff with the West, insisting Russia had not threatened to use nuclear weapons and had only responded to nuclear "blackmail" from Western leaders.

"If he has no intention, why does he keep talking about it? Why is he talking about the ability to use a tactical nuclear weapon?" Biden said in an interview with NewsNation.

"He's been very dangerous in how he's approached this," Biden said.

Putin and other Russian officials have repeatedly said in recent weeks that Russia could use nuclear weapons to protect its territorial integrity, remarks interpreted in the West as implicit threats to use them to defend parts of Ukraine that Russia claims to have annexed.

In an interview earlier on CNN, White House national security spokesperson John Kirby said it was possible Russia was considering the use of a so-called dirty bomb and was setting up a pretext to blame Ukraine. But he said the United States still had not seen any signs that was necessarily the case.

"They often blame others for that which they are doing themselves or about to do. So that's why we have to take that seriously," Kirby said of Putin's allegations.

"I'll also tell you that we're not seeing any signs, even today, that the Russians are planning to use a dirty bomb or to even make preparations for that."